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Claude Mythos Preview vs DeepSeek-V4.1-Flash-1017

Claude Mythos Preview and DeepSeek-V4.1-Flash-1017 are closely matched at 54.5 and 51.2 on the LLM Stats Score. DeepSeek-V4.1-Flash-1017 is 95.2x cheaper per token.

Anthropic · DeepSeek · Updated for 2026

Which is better?

Claude Mythos Preview and DeepSeek-V4.1-Flash-1017 are closely matched on the overall LLM Stats Score at 54.5 and 51.2.

In the 1 individual benchmarks reported for both models, Claude Mythos Preview wins 1; this is a narrower head-to-head signal than the composite indexes.

On price, DeepSeek-V4.1-Flash-1017 is roughly 95.2x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Mythos Preview

  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results

Choose DeepSeek-V4.1-Flash-1017

  • cost matters — it's about 95.2x cheaper per token
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Claude Mythos Preview
Anthropic
DeepSeek-V4.1-Flash-1017
DeepSeek
Core performance indexes
LLM Stats Score
54.5
#5
51.2
#15
Reasoning
55.6
#4
48.8
#18
Coding
43.8
#4
39.3
#14
Agents
36.6
#19
38.7
#8
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$25.00 / M
$0.30 / M
Output price
$125.00 / M
$1.20 / M
Context window
—
1,048,576

Capability indexes

Additional strengths measured across groups of related public benchmarks

3 shared
Index
Claude Mythos Preview
DeepSeek-V4.1-Flash-1017
Math
47.4#1
31.8#69
Vision
39.7#5
32.3#25
Multimodal
37.0#8
35.0#14
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

16 reported for Claude Mythos Preview · 11 for DeepSeek-V4.1-Flash-1017

1 shared

Claude Mythos Preview outperforms in 1 benchmarks (Humanity's Last Exam), while DeepSeek-V4.1-Flash-1017 is better at 0 benchmarks.

Claude Mythos Preview significantly outperforms across most benchmarks.

Fri Oct 23 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

DeepSeek-V4.1-Flash-1017 costs less

For input processing, Claude Mythos Preview ($25.00/1M tokens) is 83.3x more expensive than DeepSeek-V4.1-Flash-1017 ($0.30/1M tokens).

For output processing, Claude Mythos Preview ($125.00/1M tokens) is 104.2x more expensive than DeepSeek-V4.1-Flash-1017 ($1.20/1M tokens).

In conclusion, Claude Mythos Preview is more expensive than DeepSeek-V4.1-Flash-1017.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Fri Oct 23 2026 • llm-stats.com
Anthropic
Claude Mythos Preview
Input tokens$25.00
Output tokens$125.00
Best providerAnthropic
DeepSeek
DeepSeek-V4.1-Flash-1017
Input tokens$0.30
Output tokens$1.20
Best providerDeepSeek
Notice missing or incorrect data?

Context Window

Maximum input and output token capacity

Only DeepSeek-V4.1-Flash-1017 specifies input context (1,048,576 tokens). Only DeepSeek-V4.1-Flash-1017 specifies output context (393,216 tokens).

Anthropic
Claude Mythos Preview
Input- tokens
Output- tokens
DeepSeek
DeepSeek-V4.1-Flash-1017
Input1,048,576 tokens
Output393,216 tokens
Fri Oct 23 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Mythos Preview and DeepSeek-V4.1-Flash-1017 support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Mythos Preview

Text
Images
Audio
Video

DeepSeek-V4.1-Flash-1017

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Mythos Preview is licensed under a proprietary license, while DeepSeek-V4.1-Flash-1017 uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

Claude Mythos Preview

Proprietary

Closed source

DeepSeek-V4.1-Flash-1017

MIT

Open weights

Release Timeline

When each model was launched

DeepSeek-V4.1-Flash-1017 was released on 2026-10-17, while Claude Mythos Preview's release date is not specified.

We can confirm DeepSeek-V4.1-Flash-1017's release timeline, but cannot make a direct age comparison without Claude Mythos Preview's release date.

Claude Mythos Preview

—

DeepSeek-V4.1-Flash-1017

Oct 17, 2026

2 days ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Mythos Preview is available from Anthropic. DeepSeek-V4.1-Flash-1017 is available from DeepSeek.

Claude Mythos Preview

anthropic logo
Anthropic
Input Price:Input: $25.00/1MOutput Price:Output: $125.00/1M

DeepSeek-V4.1-Flash-1017

deepseek logo
DeepSeek
Input Price:Input: $0.30/1MOutput Price:Output: $1.20/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Claude Mythos Preview and DeepSeek-V4.1-Flash-1017 side-by-side, then vote on the output you prefer.

Claude Mythos Preview
✓ Preferred
DeepSeek-V4.1-Flash-1017
Open in Playground

FAQ

Common questions about Claude Mythos Preview vs DeepSeek-V4.1-Flash-1017.

Which is better, Claude Mythos Preview or DeepSeek-V4.1-Flash-1017?

Claude Mythos Preview and DeepSeek-V4.1-Flash-1017 are closely matched on the LLM Stats Score at 54.5 and 51.2. Claude Mythos Preview is made by Anthropic and DeepSeek-V4.1-Flash-1017 is made by DeepSeek. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Mythos Preview compare to DeepSeek-V4.1-Flash-1017 in benchmarks?

Claude Mythos Preview scores CyBench: 100.0%, USAMO25: 97.6%, GPQA: 94.6%, SWE-Bench Verified: 93.9%, CharXiv-R: 93.2%. DeepSeek-V4.1-Flash-1017 scores BabyVision: 92.5%, Chartography: 83.0%, DeepSWE 1.1: 77.0%, NL2Repo: 68.2%, AutomationBench: 60.5%.

Is Claude Mythos Preview cheaper than DeepSeek-V4.1-Flash-1017?

DeepSeek-V4.1-Flash-1017 is 83.3x cheaper for input tokens. Claude Mythos Preview costs $25.00/M input and $125.00/M output via anthropic. DeepSeek-V4.1-Flash-1017 costs $0.30/M input and $1.20/M output via deepseek.

What are the context window sizes for Claude Mythos Preview and DeepSeek-V4.1-Flash-1017?

Claude Mythos Preview supports an unknown number of tokens and DeepSeek-V4.1-Flash-1017 supports 1.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Mythos Preview and DeepSeek-V4.1-Flash-1017?

Key differences include LLM Stats Score (54.5 vs 51.2), input pricing ($25.00 vs $0.30/M), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Mythos Preview and DeepSeek-V4.1-Flash-1017?

Claude Mythos Preview is developed by Anthropic and DeepSeek-V4.1-Flash-1017 is developed by DeepSeek.

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